| Message ID | 20220616205149.16157-2-s.shtylyov@omp.ru |
|---|---|
| State | New |
| Headers | show |
| Series | Fix sloppy typing in the fast drain logic | expand |
On 6/16/22 11:51 PM, Sergey Shtylyov wrote: > ata_eh_nr_in_flight() counts the # of the active tagged commands and thus > cannot return a negative value but the result type is nevertheless *int*; > switching it to *unsigned int* (along with the local variables receiving > the function's result) helps avoiding the sign extension instructions when > comparing with or assigning to *unsigned long *ata_port::fastdrain_cnt and Grr, a typo! Should have been *unsigned long* ata_port::fastdrain_cnt... Damien, coyld you please fix it? > thus results in a more compact 64-bit code... > > Found by Linux Verification Center (linuxtesting.org) with the SVACE static > analysis tool. > > Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> [...] MBR, Sergey
On 6/18/22 03:16, Sergey Shtylyov wrote: > On 6/16/22 11:51 PM, Sergey Shtylyov wrote: > >> ata_eh_nr_in_flight() counts the # of the active tagged commands and thus >> cannot return a negative value but the result type is nevertheless *int*; >> switching it to *unsigned int* (along with the local variables receiving >> the function's result) helps avoiding the sign extension instructions when >> comparing with or assigning to *unsigned long *ata_port::fastdrain_cnt and > > Grr, a typo! Should have been *unsigned long* ata_port::fastdrain_cnt... > Damien, coyld you please fix it? OK. Note: please stop using markdown stuff like *xxx*. That is not useful and that will avoid this kind of typos. > >> thus results in a more compact 64-bit code... >> >> Found by Linux Verification Center (linuxtesting.org) with the SVACE static >> analysis tool. >> >> Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> > [...] > > MBR, Sergey
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 3307ed45fe4d..25586e16692d 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -802,11 +802,11 @@ void ata_port_wait_eh(struct ata_port *ap) } EXPORT_SYMBOL_GPL(ata_port_wait_eh); -static int ata_eh_nr_in_flight(struct ata_port *ap) +static unsigned int ata_eh_nr_in_flight(struct ata_port *ap) { struct ata_queued_cmd *qc; unsigned int tag; - int nr = 0; + unsigned int nr = 0; /* count only non-internal commands */ ata_qc_for_each(ap, qc, tag) { @@ -821,7 +821,7 @@ void ata_eh_fastdrain_timerfn(struct timer_list *t) { struct ata_port *ap = from_timer(ap, t, fastdrain_timer); unsigned long flags; - int cnt; + unsigned int cnt; spin_lock_irqsave(ap->lock, flags); @@ -870,7 +870,7 @@ void ata_eh_fastdrain_timerfn(struct timer_list *t) */ static void ata_eh_set_pending(struct ata_port *ap, int fastdrain) { - int cnt; + unsigned int cnt; /* already scheduled? */ if (ap->pflags & ATA_PFLAG_EH_PENDING)
ata_eh_nr_in_flight() counts the # of the active tagged commands and thus cannot return a negative value but the result type is nevertheless *int*; switching it to *unsigned int* (along with the local variables receiving the function's result) helps avoiding the sign extension instructions when comparing with or assigning to *unsigned long *ata_port::fastdrain_cnt and thus results in a more compact 64-bit code... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> --- drivers/ata/libata-eh.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)